Knight of Entropy

(This ability is active if you have four or more damage):When this unit attacks a vanguard, this unit gets +5000 until end of that battle. : 2When this unit is placed on , you may pay the cost. If you do, choose one of your opponent's rear-guards, and lock it. (The locked card is turned face down, and cannot do anything. It turns face up at end of the owner's turn.)